The principal of an Oxford college has launched an appeal for her youngest student, who has been missing for 11 days, to get in touch.

Child genius Sufiah Yusof, 15, pictured right, who is reading maths at St Hilda's College, has not been heard of since June 23, when she telephoned her college dean to say she was staying with a friend.

At a press conference yesterday, principal Elizabeth Llewellyn-Smith appealed for Sufiah to come forward. Sufiah's parents, Farooq and Halimahton, have urged her to contact them.

Anyone with information can call police on 01865 266000.